Abaqus CAE extremely slow

[FFFMMMAAA]

Hi all,

I am using Abaqus CAE, and I am noticing extremely slow speed when working with CAE windows. I am running a dynamic analysis of a bridge, in which I have created many steps, representing the moving load. But when I try to change an option (the time period for a step for instance) once I click in the OK button, it takes near a minute to Abaqus to keep working.

I have closed Abaqus; rebooted Windows; reduce the number of models in the same .cae archive, change working directory, etc. And something that few days ago was working fine, now it is running very slowly...

Any advice?

Thank you so much.

 

[rstupplebeen]

In the past I have had issues with openGL and Abaqus and it would appear to start and stop erratically. I do not remember the exact syntax but believe that putting a command like openGL=OFF or possibly FALSE in your environment file may help. Good luck.
Rob

Rob Stupplebeen

https://sites.google.com/site/robertkstupplebeen/

 

[FFFMMMAAA]

Thanks Rob for your reply.

Unfortunately, there isn´t any important change and Abaqus is still running very slowly...

 

[IceBreakerSours]

I don't know the reason for the delay but then, why do it CAE? Why not simply do it in the INP? Or, if it needs to be done over and over again, perhaps, a python script may be an option. Coming back to the delay, I have noticed that Abaqus CAE tends to have issues with hardware acceleration in your graphics card. I would try to slow it down or even turn it off and see if that does any good, but don't hold your breath.

http://www.eng-tips.com/faqs.cfm?fid=376

 

[FFFMMMAAA]

Thanks IceBreakerSours for the advice. I will try what you say.

I am completely new with Abaqus, and I just wanted to start using it with the CAE, and once I understand how the software works, start using input files or scripts. I used to work with Ansys, and I know the advantages of modifying input files/scripts.

I am going crazy with this issue... Modifying the value of a simple pressure load takes as long as 2-3 minutes (while "Not Responding" message appears). So just modifying the value of 160 loads, would be more than 5 hours...

 

[IceBreakerSours]

Open the INP that one of your previous runs has generated, search for Dsload in the INP. Rest should be self-explanatory.`

http://www.eng-tips.com/faqs.cfm?fid=376

 

[rstupplebeen]

If we know more details about your specific problem or the CAE file we may be able to help more. You mention many steps due to the moving load. There are amplitudes that you can apply to loads and displacements which may help with the number of steps. Depending on the specifics a representative structure providing the load and sliding along the bridge may be more efficient (user and possibly solver) and visually intuitive. I hope this helps.

Rob Stupplebeen

https://sites.google.com/site/robertkstupplebeen/

 

[FFFMMMAAA]

Many thanks to both of you.

I´ll explain my problem briefly: I have a 80-m-span deck. I want to start analyzing the dynamic problems it may present due to a moving load (vehicle). An initial approximation I am doing is divide the whole deck in small surfaces: 1m long and width depending on the size of the vehicle wheel. In order to model the moving load, I generate 81 steps: each one representing a certain position of the vehicle on the deck. I use surface loads, instead of concentrated loads, to avoid high acceleration problems. Moreover I am using ramped amplitudes (linear) to represent the approximation of the load, and dissipation of the load. Depending on the speed of the vehicle, I introduce different values of the time period.

It´s not maybe the fastest way; but it´s quite intuitive.

After analyzing some results, I wanted to change the weight of the vehicle; and consequently the value of the pressure load. And this is the moment when Abaqus CAE starts running so slowly. Even in the older models, if I try to change any parameter, it still runs very slowly.

Thank you in advance.

 

[FFFMMMAAA]

I have just tried to edit the models in a different computer and they have worked fine. Abaqus CAE was running as usual...

Do you know any option to delete temporary files or any other similar documents Abaqus could create (recovery files, etc.)?

Thank you so much.

 

[IceBreakerSours]

I am a little confused: Is CAE (the user interface of the pre/post processor) itself the source of the delay or is the solver not converging to a solution fast enough?

If you think you may have too much junk from previous runs, go to the Abaqus scratch directory (C:/Simulia/Temp on Windows) and see if .odb, .stt, .mdl files are taking up too much space.

http://www.eng-tips.com/faqs.cfm?fid=376

 

[rstupplebeen]

In addition to IBS's suggestions.

CAE files start to grow significantly because they save all the information in the creation process including deleted elements. To clean up this information and sometimes greatly reduce the file size either do a save as or save and then in (File>Compress MDB).

Are you performing this simulation in Abaqus.Explicit since you want the dynamics?

Rob Stupplebeen

https://sites.google.com/site/robertkstupplebeen/

 

[FFFMMMAAA]

IBS: the problem is the CAE preprocessor. I just want to modify some parameters such as load value, time period, etc. and when I click the OK button, this is when Abaqus takes 2-3 minutes to come back to activity. In this inactivity period, if I try to close Abaqus, suddenly the following message appears: "Unexpected Error 193", and Abaqus crashes.

I have deleted most of the files Abaqus had created from previous works (I have reduced the file size to a 10%); but the problem remains.

Rob: I have tried to "save as", changing the directory, changing the name of the CAE file, erasing different models I had in the same CAE file, changing the names of the models, etc. and the problems still remains...

And I am using the implicit method.


I really appreciate your help. I am thinking if the problem may be in the computer itself. I haven´t noticed any issues in other problems, but since Word, Excel, web browsers, etc. are not very memory-demanding, the computer could be affected. I don´t know...

Thanks a lot.

 

[IceBreakerSours]

Did you try reducing your hardware acceleration?

http://www.eng-tips.com/faqs.cfm?fid=376

 

[FFFMMMAAA]

IBS,
After reinstalling Abaqus, the problem persisted. Finally ICT people from my University created a new profile within the computer, and Abaqus has finally started working properly. I have limited capacity to make important changes in the computer, so I haven't been able to sort out what the problem was...
Thank you so much anyway!

 

[FEIM]

Hi FFFMMMAAA

I also trying to model a moving load on a bridge but I dont have much experience and im really struggling are you modeling in 3D? would you mind giving me some advice?

thanks

 

[FFFMMMAAA]

Hi FEIM,
I am not really an expert, and you better ask someone who has more experience in this field. But what I am doing right now is:
- Using CAE. Later, I will start using input files or scripts; but first, I want to make sure that what I am doing is right.
- I am using a 3D model of the bridge, by combination of shell, beam and truss elements.
- Since the deck I have modeled is built by shell elements, I have made "partitions" of the deck, creating surfaces where I will apply "surface loads".
- I have created as many steps as load positions. I have assigned each step a certain duration: depending on the speed of the vehicle.
- In each step I create a surface load for the current position of the vehicle. And I "supress" the load of the previous step.
- In order to have more continuous functions, I am using ramped amplitudes for the loads: consequently I can model in a more realistic way the vehicle load (by taking into account the approaching and the leaving effects).
- I am using the implicit method to solve the problem, which takes quite a long time.
Maybe in a couple of weeks I will change the approach to this problem, but so far this is how I am working.
Regards.